Even as attendance dropped overall at area museums and animal attractions in 2013, it was a very good year for horticulture.

The Chicago Botanic Garden had more than 1 million visitors for the first time since it opened in 1972, a 5 percent increase over 2012, while the Morton Arboretum climbed to 885,000 visitors in 2013, up from 809,000 the year before.

“There is a growing demand for places where people can visit that are centered on the outdoors, on the evironment and health, well being, inspiration — and both of our institutions are a very good value,” said Sophia Shaw Siskel, president and CEO of the 385-acre Botanic Garden, located in Glencoe.

The arboretum's boost could largely be attributed to a new, outdoor, holiday-season lights attraction, “Illumination,” which drew 84,000 visitors, most of them during a cold and snowy December.

Overall attendance for the 15 institutions that comprise Museums Work for Chicago, which includes 11 members of the Museums in the Park coalition and four other Cook County attractions, went down to 14.8 million from 15.1 million, a 2 percent decline from 2012 to 2013, according to figures released Monday by the Museums Work coalition.

The arboretum, in Lisle, is not part of the Museums Work group and provided its attendance figures separately.

While the three most popular area attractions — all animal havens — accounted for more than half of the coalition’s attendance, they reported attendance declines ranging from 1 to 7 percent compared with the previous year.

They are the free Lincoln Park Zoo, with 3.46 million estimated visitors (down from 3.51 million); Brookfield Zoo, with 2.17 million (2.34 million); and Shedd Aquarium, with 2.02 million (2.17 million).

Joe Couceiro, Brookfield's vice president of marketing and communications, said the decline was the result of “a long winter” at the beginning of 2013, which then ended with the rough December.

Overall, though, “we had a very good year,” he said. “We had a very strong summer and really caught up.”

At Shedd Aquarium, the 7 percent drop came despite the introduction of a new, warm-weather attraction, the Stingray Touch petting pool.

But executive vice president of guest experience Amy Ritter Cowen chose to accentuate the positive, emphasizing the aquarium's remaining above the 2 million threshold and being the top paid attraction in city boundaries.

“That is just a fantastic showing of support,” she said.

The aquarium trails Lincoln Park and Brookfield Zoos in attendance and is well ahead of the Art Institute of Chicago (1.54 million), the Museum of Science and Industry (1.4 million), and the Field Museum (1.29 million).

To become the only other member of the million-plus club, the Chicago Botanic Garden has had the best five-year growth trend in the group, climbing each year from 2009's 890,000 visitors.

“It’s a wonderful milestone at an institution that is just approaching its 42nd birthday,” said Shaw Siskel. “It really puts us up there with all the leading civic institutions in Chicago. If you think about it, we don’t have a roof, so we really work for it in the winter.”

Five other institutions in the coalition showed attendance gains in 2013. Chicago History Museum admissions grew by 13 percent, DuSable Museum of African American History by 6 percent, the Art Institute by 5 percent and the Field Museum by 3 percent.

The Institute of Puerto Rican Arts and Culture, marking its first full year as a member of the coalition, grew attendance by 19 percent, to nearly 18,000.

The Chicago Children's Museum, Peggy Notebaert Nature Museum, National Museum of Mexican Art and Museum of Science and Industry joined Brookfield and Shedd in being down by at least 4 percent.

Lollapalooza 2015 is underway in Chicago's Grant Park. Join our coverage of the three-day music festival, as Paul McCartney, Sam Smith, Metallica and Florence and the Machine headline. On the Tribune app? Click here to see the live blog.